Electrical switch-board and signaling apparatus



(NoMo'deL) v T. W. LANE & P. W. HARRINGTON.

ELEGTRIGAL- SWITCH BOARD AND S IGNAL'ING APPARATUS. 7 No. 262,059. Patented Au 1, 1882'.

UNITED STAT S I ATENT OFFICE.

THOMAS W. LANE AND FRANK W. HARRINGTON, OF BOSTON, ASSIGNORS TO CHARLES WVILLIAMS, JR OF SOMERVILLE, MASSACHUSETTS.

ELECTRICAL SWITCH-BOARD AND SIGNALING APPARATUS.

SPECIFICATION forming part. of Letters Patent No. 262,959, dated August 1, 1882.

Application filed June 9, 1882. (No model.)

To all whom it may 001201711.

Be it known that we, THOMAS W. LANE and FRANK W. HARRINGTON, both of Boston, in the countyot' Suffolk and State of Massachusetts, have invented certain Improvements in Electrical Switch-Boards and Signaling Apparatus, of which the following is a specification.

This invention relates to telephonic switchboards used in central oflices and employing 1o line-circuit strips adapted to be connected by plugs through connecting-strips.

The invention has for its object to provide means whereby the necessary operations of calling and arranging circuits for intercommunication between subscribers can be performed with the utmost directness, simplicity, and economy of apparatus.

The invention relates directly to the improvement forming the subject natter of Patout No. 250,081, granted to Thomas W. Laue November 29,1881, in which a listening-circuit is shown and described composed of two horizontal metallic strips arranged at the lower edge of a switch-board and separated by a space from one another, with orilices extending through the board opposite each line-strip upon the rear of the board, so that by the insertion of a special plug through any such orifi'ce connection may be made between said line- 0 strips and the horizon-tat metallic strips, and

thus complete a listening-circuit, the line-stri p being capable of separation at points opposite said orifice, and the separating-plug being similar to that described in said patent.

3 5 Our present invention consists in the arrangement of circuits and apparatus whereby when said plug is inserted into the lino-strip the operators local circuit may be cut outand a signal sent to line, or when two line-strips 0 are connected together through the switchboard they may be temporarily separated from each other and a signal sent to either one of the two without disturbance or annoyance to the other, as we will now proceed to describe.

5 In our present invention the line enters the line-strip, and passes through the annunciator to ground in the usual manner. We attach a wire to the upper one of the pair of horizontal strips, which, after passing through the operators transmitter and telephone, is in like manner secured to the lower one of said strips, so that when the plug is inserted into the separable line-strip the said instruments are in the line-circuit. \Ve attach another wire to the lower strip of the pair, which is connected to 5 ground through a generator of electricity, which may be either a battery or a magnetoelectric machine. For most circuits we prefer the latter. In the course of this wire we insert ayonepoint switch, by means of which all connection to the ground or generator may be out 011'.

In the operation of our invention we employ a plug composed of two metallic springs supported and insulated from each other by a 6 stock of insulating material, one of the springs being bent at right angles at its free end to form a stop to rest against one of the horizontal strips when inserted between them. The other spring is made longer, and has a button 0 or knob of some insulating material secured to its free end.

Of the accompanying drawings, forming a part of this specification, Figure l is a diagram and sectional view, showing our invention with the plug inserted, forming a completed listeningcircuit. Fig. 2 represents a similar view, showing the said circuit broken. Fig. 3 represents an enlarged View of the spring-plug.

The same letters of reference indicate the same parts in all the figures.

In the drawings, A is the body of the switchboard, upon the rear side of which are'secured the spring line-strips a and a, which normally rest against each other firmly by their own re- 8 5 silience. ,Upon the face of the board A are two horizontal metallic rods or strips, 7) b, directly opposite the separable springs a a. Between the strips 1) b are orifices h through the board for the insertion of the plugs, hereinafter de- 0 scribed. To upper rod, 1), is connected a wire, 1, which, after passing through transmitter B and hand-telephone O, is attached to the lower rod, 1). From the lower rod or strip, 11, a wire, 2, runs to a one-point switch, 0, through mag- 5 neto or other generator D to earth G by wire 3.

E is a connecting-plug, formed of a stock, 9, of insulating material, upon one face or side of which is a flat metal spring, d, permanently plete'a listening-circuit which is susceptible of fixed at one end of the plug, and so arranged as to normally spring away from the stockg at its free end. The free end is bent over at right angles to form a stop to limit its insertion into the switch-board, and to rest upon one of the rods 1) b. Upon the opposite side of the stock g another spring, 6, is arranged in a similar manner. a button or knob,f, of insulating material. A portion of the surface of the stock 9 is cutaway under the spring 6, forming a recess, t, to allow the spring to be depressed from contact with rod 1/ when inserted between said rods I b, as hereinafter described.

The operation is as follows: Acall being re ceived at the central office, the annunciator of the line-circuit on which the call is sent drops, the operator inserts a plug, E, as shown, into the line-strip, with the spring 6 uppermost, presses the knobf, causing the springe to separate from the strip 1), thus cutting off the normal-line ground, and, turning the switch 0 to its button, sends asignal to thecalling party by means of the generator D, a circuit being thus made from ground through generator D, wire 2, rod 1), spring 6?, spring a. to line. By releasing the knob f the listening-circuit is made complete and the wants of the calling party ascertained. The desired line-strip haviug been plugged or connected with that of the calling party through a connecting-strip of the switch-board, the plug E is withdrawn from the calling-line and inserted into the desired line-circuit. By pressing down the knob f of the plug E connection between the two lines is temporarily broken, and a calling-signal can then be sent by means of the generator D to the desired party without ringing into the ear of the party first called. By releasing the knob and turning the switch 0 from its but- IZOII'IlJG two lines are placed in circuit again, with the listening telephones O B looped in.

It will be seen that by the use of our improved plu git is possible to automatically com Upon the free end of the spring eis i being temporarily opened, thus breaking the normal line to ground and making a new ground and signaling circuit with any linecircuit on the switch-board.

We claim- 1. The combination of a switch-board having a splies of line-circuit strips, each adapted to be separated into two distinct parts at a given point, a circuit comprising two strips, 1) 1), arranged, as described, with relation to the points where the line-circuit strips are separable,'a magneto-generator or its equivalent connected with the strip 1), a switch adapted to cut the generator into and out of the circuit, and a plug, substantially such as herein described, adapted to separate one of the linecircuit strips into two parts and connect the strips b b, respectivelypvith the separated parts.

of said line-circuit strip, or to connect one strip and disconnect the other, as described, whereby when said plug is inserted into the linestrip the operators local circuit can he cutout and a signal can be sent to line, or when two line-strips are connected through the switchboard they may be temporarily separated from each other and a signalmay be sent to either independently, as set forth.

2. The improved plug for an electrical switch-board, composed of the outwardly-projecting springs 01 eand a stock or body, {1, supporting and insulating said springs, and provided with a recess, 6, adapted to receive one of said springs, substantially as and for the purpose specified.

In testimony whereof we have signed our names to this specification,in the presence of two subscribing witnesses, this 7th dayof June, A. D. 1882.

THOMAS W. LANE. FRANK W. HARRINGTON.

Witnesses:

G. F. BROWN, A. L. WHITE. 

